Problem: Solve the following expression and give your answer as a fraction. $ -0.1 \times \dfrac{3}{10} = {?} $
First get all of the numbers as simplified fractions. $ -0.1 = -\dfrac{1}{10} $ Now we have: $ -\dfrac{1}{10} \times \dfrac{3}{10} = {?} $ $ \phantom{ -\dfrac{1}{10} \times \dfrac{3}{10} } = \dfrac{-1 \times 3 } {10 \times 10 } $ $ \phantom{ -\dfrac{1}{10} \times \dfrac{3}{10} } = -\dfrac{3}{100} $